Recently, when key operation information of a substation cannot be exchanged in a power system due to a network problem, an operator's manipulation and determination of an automated device may be interrupted and thus large-scale economic and social damages such as a power failure accident may occur.
Thus, the International Electro-technical Commission (IEC) prescribed a standard (IEC62351-7) for network and system management (NSM) information specialized for power systems and provided it to global utilities, thereby contributing to stable operation of power systems.
The NSM information according to the above standard is different from a general IT environment in that a main path and alternative paths of a network, data type, etc. are defined beforehand according to a specific pattern so that an alarm may be generated when a network path or data which does not match the specific pattern occurs.
According to the standard (IEC62351-7) for the NSM information specialized for power systems, an object for connection and maintenance of a network is defined as in Table 1 below.
TABLE 1Name of informationClassification(object)TypeDescriptionConfigurationConnRtryCntIntegerNumber of times to retry to connect tovaluenetwork to change state from temporaryerror state to permanent error stateConnRtryTmmsTimeTime interval between retries ofconnection in temporary error stateConnFailRtryCntIntegerNumber of times to retry to connect inpermanent error stateConnFailRtryTmmsTimeTime interval between retries ofconnection in permanent error stateNetAltPthOI ArrayList of alternative paths to main pathOperationalRsTmmsTimeTotal time period after resetvalueConnTotTmmsTimeTotal connection time after resetConnCurTmmsTimeCurrent-connection-state maintenancetime after connection to networkConnAvTmmsTimeAverage connection timeConnFailTotCountNumber of errors occurring in normalconnections stateConnRejIntegerNumber of times to reject trying toconnectAltPthStStatusStates of alternative paths to main pathAlarmConnAlmAlarmAlarm for temporary connection errorConnFailAlmAlarmAlarm for permanent connection errorConnFlovAlmAlarmAlarm for alternative connection
In Table 1 above, the ‘configuration value’ represents values designated beforehand for network maintenance, the ‘operational value’ represents state values generated during actual operation of the network, and the ‘alarm’ represents important information to be delivered to an operator.
However, information which an operator can intuitively know among the information shown in Table 1 above (standard object information) is only information indicating whether an alarm is generated or not. The information shown in Table 1 above does not include information enabling the operator to determine current stability of a network. That is, only a major problem or an error of the network is reported to the operator and information enabling the operator to predict the problem or error beforehand is not provided to the operator.
For example, the scale of an electric power accident may vary according to an operator's initial response thereto as known in previous electric power accident cases (e.g., the California electricity crisis, the South Korea 915 rolling blackout, etc.). That is, the scale of the electric power accident is significantly influenced by a response time of several seconds to several tens of seconds at an initial stage thereof. Thus, if information enabling the operator to predict the electric power accident is provided to the operator before an alarm is generated, the scale of this accident may be dramatically reduced.
However, information directly delivered to an operator among the NSM information according to the standard prescribed by the IEC is only alarm information (i.e., an alarm regarding a network error result), and information enabling the operator to predict a risk of an electric power accident is not provided. Accordingly, the operator cannot notice a state of a network before a network error occurs and thus cannot respond to prevent occurrence and expansion of an accident before the network error occurs (or before an alarm is generated).
The background technology of the present invention is disclosed in Korean Patent No. 10-0728823, entitled “System and Method for Estimating an Voltage Stability of Power System” (registered on Jun. 8, 2007).